/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * -----------------------
 * DefaultKeyedValues.java
 * -----------------------
 * (C) Copyright 2002-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   Thomas Morgner;
 *
 * Changes:
 * --------
 * 31-Oct-2002 : Version 1 (DG);
 * 11-Feb-2003 : Fixed bug in getValue(key) method for unrecognised key (DG);
 * 05-Mar-2003 : Added methods to sort stored data 'by key' or 'by value' (DG);
 * 13-Mar-2003 : Implemented Serializable (DG);
 * 08-Apr-2003 : Modified removeValue(Comparable) method to fix bug 717049 (DG);
 * 18-Aug-2003 : Implemented Cloneable (DG);
 * 27-Aug-2003 : Moved SortOrder from org.jfree.data --> org.jfree.util (DG);
 * 09-Feb-2004 : Modified getIndex() method - see bug report 893256 (DG);
 * 15-Sep-2004 : Updated clone() method and added PublicCloneable
 *               interface (DG);
 * 25-Nov-2004 : Small update to the clone() implementation (DG);
 * 24-Feb-2005 : Added methods addValue(Comparable, double) and
 *               setValue(Comparable, double) for convenience (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 31-Jul-2006 : Added a clear() method (DG);
 * 01-Aug-2006 : Added argument check to getIndex() method (DG);
 * 30-Apr-2007 : Added insertValue() methods (DG);
 * 31-Oct-2007 : Performance improvements by using separate lists for keys and
 *               values (TM);
 * 21-Nov-2007 : Fixed bug in removeValue() method from previous patch (DG);
 *
 */

package net.droidsolutions.droidcharts.core.data;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;

import net.droidsolutions.droidcharts.common.SortOrder;

/**
 * An ordered list of (key, value) items. This class provides a default
 * implementation of the {@link KeyedValues} interface.
 */
public class DefaultKeyedValues implements KeyedValues, Cloneable, Serializable {

	/** For serialization. */
	private static final long serialVersionUID = 8468154364608194797L;

	/** Storage for the keys. */
	private ArrayList keys;

	/** Storage for the values. */
	private ArrayList values;

	/**
	 * Contains (key, Integer) mappings, where the Integer is the index for the
	 * key in the list.
	 */
	private HashMap indexMap;

	/**
	 * Creates a new collection (initially empty).
	 */
	public DefaultKeyedValues() {
		this.keys = new ArrayList();
		this.values = new ArrayList();
		this.indexMap = new HashMap();
	}

	/**
	 * Returns the number of items (values) in the collection.
	 * 
	 * @return The item count.
	 */
	public int getItemCount() {
		return this.indexMap.size();
	}

	/**
	 * Returns a value.
	 * 
	 * @param item
	 *            the item of interest (zero-based index).
	 * 
	 * @return The value (possibly <code>null</code>).
	 * 
	 * @throws IndexOutOfBoundsException
	 *             if <code>item</code> is out of bounds.
	 */
	public Number getValue(int item) {
		return (Number) this.values.get(item);
	}

	/**
	 * Returns a key.
	 * 
	 * @param index
	 *            the item index (zero-based).
	 * 
	 * @return The row key.
	 * 
	 * @throws IndexOutOfBoundsException
	 *             if <code>item</code> is out of bounds.
	 */
	public Comparable getKey(int index) {
		return (Comparable) this.keys.get(index);
	}

	/**
	 * Returns the index for a given key.
	 * 
	 * @param key
	 *            the key (<code>null</code> not permitted).
	 * 
	 * @return The index, or <code>-1</code> if the key is not recognised.
	 * 
	 * @throws IllegalArgumentException
	 *             if <code>key</code> is <code>null</code>.
	 */
	public int getIndex(Comparable key) {
		if (key == null) {
			throw new IllegalArgumentException("Null 'key' argument.");
		}
		final Integer i = (Integer) this.indexMap.get(key);
		if (i == null) {
			return -1; // key not found
		}
		return i.intValue();
	}

	/**
	 * Returns the keys for the values in the collection.
	 * 
	 * @return The keys (never <code>null</code>).
	 */
	public List getKeys() {
		return (List) this.keys.clone();
	}

	/**
	 * Returns the value for a given key.
	 * 
	 * @param key
	 *            the key (<code>null</code> not permitted).
	 * 
	 * @return The value (possibly <code>null</code>).
	 * 
	 * @throws UnknownKeyException
	 *             if the key is not recognised.
	 * 
	 * @see #getValue(int)
	 */
	public Number getValue(Comparable key) {
		int index = getIndex(key);
		if (index < 0) {
			throw new UnknownKeyException("Key not found: " + key);
		}
		return getValue(index);
	}

	/**
	 * Updates an existing value, or adds a new value to the collection.
	 * 
	 * @param key
	 *            the key (<code>null</code> not permitted).
	 * @param value
	 *            the value.
	 * 
	 * @see #addValue(Comparable, Number)
	 */
	public void addValue(Comparable key, double value) {
		addValue(key, new Double(value));
	}

	/**
	 * Adds a new value to the collection, or updates an existing value. This
	 * method passes control directly to the
	 * {@link #setValue(Comparable, Number)} method.
	 * 
	 * @param key
	 *            the key (<code>null</code> not permitted).
	 * @param value
	 *            the value (<code>null</code> permitted).
	 */
	public void addValue(Comparable key, Number value) {
		setValue(key, value);
	}

	/**
	 * Updates an existing value, or adds a new value to the collection.
	 * 
	 * @param key
	 *            the key (<code>null</code> not permitted).
	 * @param value
	 *            the value.
	 */
	public void setValue(Comparable key, double value) {
		setValue(key, new Double(value));
	}

	/**
	 * Updates an existing value, or adds a new value to the collection.
	 * 
	 * @param key
	 *            the key (<code>null</code> not permitted).
	 * @param value
	 *            the value (<code>null</code> permitted).
	 */
	public void setValue(Comparable key, Number value) {
		if (key == null) {
			throw new IllegalArgumentException("Null 'key' argument.");
		}
		int keyIndex = getIndex(key);
		if (keyIndex >= 0) {
			this.keys.set(keyIndex, key);
			this.values.set(keyIndex, value);
		} else {
			this.keys.add(key);
			this.values.add(value);
			this.indexMap.put(key, new Integer(this.keys.size() - 1));
		}
	}

	/**
	 * Inserts a new value at the specified position in the dataset or, if there
	 * is an existing item with the specified key, updates the value for that
	 * item and moves it to the specified position.
	 * 
	 * @param position
	 *            the position (in the range 0 to getItemCount()).
	 * @param key
	 *            the key (<code>null</code> not permitted).
	 * @param value
	 *            the value.
	 * 
	 * @since 1.0.6
	 */
	public void insertValue(int position, Comparable key, double value) {
		insertValue(position, key, new Double(value));
	}

	/**
	 * Inserts a new value at the specified position in the dataset or, if there
	 * is an existing item with the specified key, updates the value for that
	 * item and moves it to the specified position.
	 * 
	 * @param position
	 *            the position (in the range 0 to getItemCount()).
	 * @param key
	 *            the key (<code>null</code> not permitted).
	 * @param value
	 *            the value (<code>null</code> permitted).
	 * 
	 * @since 1.0.6
	 */
	public void insertValue(int position, Comparable key, Number value) {
		if (position < 0 || position > getItemCount()) {
			throw new IllegalArgumentException("'position' out of bounds.");
		}
		if (key == null) {
			throw new IllegalArgumentException("Null 'key' argument.");
		}
		int pos = getIndex(key);
		if (pos == position) {
			this.keys.set(pos, key);
			this.values.set(pos, value);
		} else {
			if (pos >= 0) {
				this.keys.remove(pos);
				this.values.remove(pos);
			}

			this.keys.add(position, key);
			this.values.add(position, value);
			rebuildIndex();
		}
	}

	/**
	 * Rebuilds the key to indexed-position mapping after an positioned insert
	 * or a remove operation.
	 */
	private void rebuildIndex() {
		this.indexMap.clear();
		for (int i = 0; i < this.keys.size(); i++) {
			final Object key = this.keys.get(i);
			this.indexMap.put(key, new Integer(i));
		}
	}

	/**
	 * Removes a value from the collection.
	 * 
	 * @param index
	 *            the index of the item to remove (in the range <code>0</code>
	 *            to <code>getItemCount() - 1</code>).
	 * 
	 * @throws IndexOutOfBoundsException
	 *             if <code>index</code> is not within the specified range.
	 */
	public void removeValue(int index) {
		this.keys.remove(index);
		this.values.remove(index);
		rebuildIndex();
	}

	/**
	 * Removes a value from the collection.
	 * 
	 * @param key
	 *            the item key (<code>null</code> not permitted).
	 * 
	 * @throws IllegalArgumentException
	 *             if <code>key</code> is <code>null</code>.
	 * @throws UnknownKeyException
	 *             if <code>key</code> is not recognised.
	 */
	public void removeValue(Comparable key) {
		int index = getIndex(key);
		if (index < 0) {
			throw new UnknownKeyException("The key (" + key
					+ ") is not recognised.");
		}
		removeValue(index);
	}

	/**
	 * Clears all values from the collection.
	 * 
	 * @since 1.0.2
	 */
	public void clear() {
		this.keys.clear();
		this.values.clear();
		this.indexMap.clear();
	}

	/**
	 * Sorts the items in the list by key.
	 * 
	 * @param order
	 *            the sort order (<code>null</code> not permitted).
	 */
	public void sortByKeys(SortOrder order) {
		final int size = this.keys.size();
		final DefaultKeyedValue[] data = new DefaultKeyedValue[size];

		for (int i = 0; i < size; i++) {
			data[i] = new DefaultKeyedValue((Comparable) this.keys.get(i),
					(Number) this.values.get(i));
		}

		Comparator comparator = new KeyedValueComparator(
				KeyedValueComparatorType.BY_KEY, order);
		Arrays.sort(data, comparator);
		clear();

		for (int i = 0; i < data.length; i++) {
			final DefaultKeyedValue value = data[i];
			addValue(value.getKey(), value.getValue());
		}
	}

	/**
	 * Sorts the items in the list by value. If the list contains
	 * <code>null</code> values, they will sort to the end of the list,
	 * irrespective of the sort order.
	 * 
	 * @param order
	 *            the sort order (<code>null</code> not permitted).
	 */
	public void sortByValues(SortOrder order) {
		final int size = this.keys.size();
		final DefaultKeyedValue[] data = new DefaultKeyedValue[size];
		for (int i = 0; i < size; i++) {
			data[i] = new DefaultKeyedValue((Comparable) this.keys.get(i),
					(Number) this.values.get(i));
		}

		Comparator comparator = new KeyedValueComparator(
				KeyedValueComparatorType.BY_VALUE, order);
		Arrays.sort(data, comparator);

		clear();
		for (int i = 0; i < data.length; i++) {
			final DefaultKeyedValue value = data[i];
			addValue(value.getKey(), value.getValue());
		}
	}

	/**
	 * Tests if this object is equal to another.
	 * 
	 * @param obj
	 *            the object (<code>null</code> permitted).
	 * 
	 * @return A boolean.
	 */
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		}

		if (!(obj instanceof KeyedValues)) {
			return false;
		}

		KeyedValues that = (KeyedValues) obj;
		int count = getItemCount();
		if (count != that.getItemCount()) {
			return false;
		}

		for (int i = 0; i < count; i++) {
			Comparable k1 = getKey(i);
			Comparable k2 = that.getKey(i);
			if (!k1.equals(k2)) {
				return false;
			}
			Number v1 = getValue(i);
			Number v2 = that.getValue(i);
			if (v1 == null) {
				if (v2 != null) {
					return false;
				}
			} else {
				if (!v1.equals(v2)) {
					return false;
				}
			}
		}
		return true;
	}

	/**
	 * Returns a hash code.
	 * 
	 * @return A hash code.
	 */
	public int hashCode() {
		return (this.keys != null ? this.keys.hashCode() : 0);
	}

	/**
	 * Returns a clone.
	 * 
	 * @return A clone.
	 * 
	 * @throws CloneNotSupportedException
	 *             this class will not throw this exception, but subclasses
	 *             might.
	 */
	public Object clone() throws CloneNotSupportedException {
		DefaultKeyedValues clone = (DefaultKeyedValues) super.clone();
		clone.keys = (ArrayList) this.keys.clone();
		clone.values = (ArrayList) this.values.clone();
		clone.indexMap = (HashMap) this.indexMap.clone();
		return clone;
	}

}
